The invention relates to an electromagnetic drive system or motor with an integrated path signal generator in accordance with the electrodynamic effective principle. Such motors use the power EMF charges of a conductor winding induced with current in a preferably permanent excited magnetic field. The magnetic field can be principally generated not only by one permanent magnet but also by a second conductor winding which is induced with a current, however, in this case, specific permanent excited motors are of interest. For using the effective power between the two main components of the motor, the permanent magnet and the coil system for the linear or rotational movement, one of the two components (for example, the coil system) is stationary and the other (in the exemplified embodiment the permanent magnet) represents the movable output of the arrangement.
Motors of this design, for example, in accordance with DE 18 08 900 do not have internal gauges and self locking means. In order to start up or to hold a position it requires a complete control circuit with at least one measuring system for the path measuring or if constant equal lengths are required one needs a measurement for the speed (for example, Kallenbach, E. Bogelsack.G.: Geratetechnische Antriebe.Carl Hanser Verlag, Munchen, Wien 1991, pages 285 etc.).
External control systems which are coupled to the motor or internal control systems are known which are mechanically integrated into the total structure. However, these systems generally have separate structural parts which are independent from the drive windings, for example, control coils (for example, Kallenbach, E Bogelsack.G. Geratetechnische Antriebe.Carl Hanser Verlag, Munchen, Wien 1991, pages 97 etc. and 249 etc.). Also known are motors or circuits which shunt a speed proportional control signal from the voltage drop through the drive winding (for example, Kuhne H.: Examples for control and regulating circuits with direct current small motors. Amateurreihe electronica. Band 176. Militarverlag, Berlin 1979). For the path control, separate control systems, or at least additional structural units (control coils), are presently required.
On the other hand, motors are known, preferably rotary motors, which use the drive winding simultaneously for recognizing the position of transmissions between different field ranges and thus for shunting a communication signal through the pick up of saturation manifestations (for example, in EPE Journal, Vol.2, No.1, 1992, 5.25 to 34). However, a considerable effort is required for this crude position arrangement. An exact proportional control signal for an absolute control of the runner position cannot be practically shunted off.
The use of a position sensor in rotary or linear direct current motors, without any additional control system, had been suggested in EP 457 389, whereby the different coil parts of the motor are electromagnetically coupled through a short circuit winding. The short circuit winding is mounted on the other coil-less passive motor part and couples in a control signal in addition to the position signal into one of the part coils so as to obtain a transformer-like inductive coupling into at least another part coil which is not induced by the control signal being dependent on the position of the passive motor part, which then could be used as a control signal for the runner position. The disadvantage of this solution is the necessity of a short circuit winding on the passive motor part, on the one hand, but more the fact that the active motor part (stator with coil system) must not carry its own inductive coupling in the form of a short circuit winding or an electrically conductive magnetic yoke, on the other hand. However, due to the absence of a magnetic yoke, the motor power, and therefore the useability of the motor, is very much diminished.
A method for sensing the path of a direct current linear motor through the dual use of the coil parts as drive winding and control winding through the additional admittance of the direct current set signal with a control alternate voltage and subsequent evaluation in the form of a differential or quotient formation between the amplitudes of the part control alternate voltages is disclosed in German petty patent No.297 05 315.9. However, this device has the disadvantage that it is useable only for very small motor drive capacities due to the use of a continuous operating, analog capacity end step. Also, because the filter used in this method for preparing the signal, the control dynamic is very much impaired. Moreover, the two aforementioned suggestions require an additional control alternate voltage for generating the path signal.